Associate Professor Microbiology/Consultant Microbiologist, Aga Khan University in Nairobi, 2006–to date
Faculty and External Examiner, Jomo-Kenyatta University of Agriculture and Technology, Kenya, 2001–to date
Chief Medical Specialist, Consultant Microbiologist and Head of the Department of Laboratory Medicine, Department of Medical Microbiology, Kenyatta National Hospital and College of Health Sciences, University of Nairobi, Kenya, 2000–2006
Visiting Collaborating Scientist, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya, 1999 to date
Senior Medical specialist and Consultant Microbiologist, Department of Laboratory Medicine and Department of Medical Microbiology, Kenyatta National Hospital and College of Health Sciences, University of Nairobi, 1997–2000
Reader (equivalent of Associate Professor), Department of Microbiology, University College of Medical Sciences, Delhi, India, 1993–1997
Senior lecturer, Department of Microbiology, University College of Medical Sciences, Delhi, India, 1990–1993
Lecturer, Department of Microbiology, University College of Medical Sciences Delhi, India, 1988-1990
Senior Research Officer, Department of Microbiology and Cytology Research Centre, Maulana Azad Medical College, New Delhi, India, 1985-1987
Professional associations

International Society of Chemotherapy, 2012 to date
Member, International Society of Chemotherapy, 2012 to date
Infection Control Africa Network, 2012 to date
Kenya Association of Clinical Pathologists, 2001 to date
Association of Pathologist of East, Central and South Africa, 2002 to date
European Society of Clinical Microbiology Infectious Diseases, 1995 to date
International Society of Infectious Diseases, 1994 to date